This page provides information on how the latest version of V-Ray handles scenes saved with previous versions of V-Ray.
V-Ray 3.0 adds a number of rendering optimization features. However, for compatibility reasons, some features and workflows have been adjusted and are discussed in detail below.
Opening a Scene
When a scene saved with V-Ray 2 is loaded in Rhino (using V-Ray 3), an upgrade script will go through all the scene assets and features to account for incompatibilities. All lights, materials, and special objects will be upgraded from groups to a new component definition system. This upgrade can take some time, but only happens the first time the scene is opened in Rhino with V-Ray 3. When the scene is saved, the updates are saved with it.
The V-Ray materials list in the new Asset Editor is synched to match the Rhino scene materials each time a scene file is opened. This prevents V-Ray from overwriting any material changes introduced while V-Ray was not present (not loaded or installed).
Wipe Scene Tool
Found in Extensions > V-Ray > Tools, this new tool can purge the scene of all V-Ray related information. Additional functionality includes the optional removal of any unused Rhino materials and component definitions.
The method in which render quality is handled in V-Ray 3.4 has changed. This process is now much simpler and straight forward. The local Subdivs parameters in materials, lights and camera have been hidden and will no longer have an effect.
The DMC Sampler settings are also hidden and set up with their most optimized values.
The Image Sampler options previously available are no longer in the UI. An updated version of the Adaptive DMC sampler is enabled and used for optimal rendering performance.
If the Global subdivis mult has been used in V-Ray 2.0, it will have no effect in V-Ray 3.4.
As good practice, we recommend a reset of all the render settings (‘Revert to Default Render Settings’) when loading a V-Ray 2 scene. Starting fresh is extremely easy thanks to the Quality slider and the new approach. Keep in mind that, being part of the render settings, any Environment textures will also be disconnected and colors reset.
Loading ‘.vropt’ or ‘.visopt’ files created in previous V-Ray versions is not recommended. Some outdated parameters may cause unexpected results. Using the new streamlined quality presets, and then fine-tuning the settings before saving them in a new ‘.vropt’ file is the recommended approach.
When Interactive rendering is enabled, the image will always resolve to perfect quality given enough time. No quality settings are available in this mode. The only setting that can be adjusted is the Global Illumination / Brute Force depth (this is the number of secondary diffuse light bounces). Keep in mind that the Interactive rendering process will not automatically save an output image. It's primary purpose is to give the user interactive feedback for every scene change that occurs. However, it is possible to save the image at any time, from the V-Ray frame buffer menu.
The Quality slider available in the Renderer roll-out is the easiest way to control quality and render speed. It changes image sampling settings and tweaks GI parameters for all possible GI engines at the same time. This means that for any GI engine combination selected, the slider will have the desired effect.
The Quality Slider presets are not the same as in previous versions of V-Ray. This means that scenes using old presets will instead have their slider set to Custom.
In case custom quality settings are needed, the image sampler parameters are still available and can be changed (Noise limit / Min Subdivs / Max Subdivs). They affect the overall image sampling and anti-aliasing, as well as blurry camera effects such as Motion Blur and Depth of Field.
The Shading rate parameter available under Optimizations is another more advanced tool that affects secondary blurry effect sampling. It has an effect for blurry material reflections, refractions, translucency, … as well as area light/shadow quality. We recommend setting / leaving the Shading Rate to a value of 6 when used together with the Quality slider.
The Shading Rate has no effect when GPU Acceleration is enabled
The V-Ray Denoiser render element has been added to V-Ray 3 and can help with rendering noise-free images. It can be created as a render element and is controlled with a set of parameters. The next time an image is rendered with this element present and enabled, a Denoiser render element will then be available in the VFB with the post-processed, denoised result.
In V-Ray 3, the V-Ray Physical Camera’is enabled and always on. The Exposure parameter of the camera is hidden and enabled, which means that F-Number, Shutter Speed and ISO will always influence the rendered image exposure.
If a non-physical camera was used in a V-Ray 2.0 scene, that camera is automatically converted when the scene is loaded in V-Ray 3.4. An average Exposure Value (EV) will be applied, and the overall image exposure might change (i.e. it may not match results from V-Ray 2.0). This may be addressed by changing the EV value in the camera parameters roll-out, or by tweaking the VFB exposure slider.
Simple and Advanced Camera Parameters
The camera in V-Ray 3.4 has two parameter modes: Basic Settings and Advanced Settings. The Basic mode uses EV for exposure control and Defocus for DOF, while the Advanced mode shows the F-Number, Shutter Speed and ISO parameters for editing.
With the Basic Camera Settings enabled, the defocus (DOF) can be changed while the image exposure remains the same.
The Environment roll-out and management has been changed.
There is now a separate Background environment slot which is visible as a background by default, and is visible to all secondary rays (GI, reflection, refractions).
Overriding the environment for specific ray type can easily be accomplished in the Environment Overrides roll-out.
The Color Mapping roll-out is no longer available in V-Ray 3. The Type parameter is automatically set to Linear Multiply.
The Gamma value is set to 2.2 and Don’t affect colors option is enabled.
This means that V-Ray is always rendering linear floating color images, and the sRGB button in the VFB should be always On to display a proper image. This simplifies the color management workflow and assures that the render elements will be composited correctly in an external post-production application.
If an 8bit file is saved through the VFB or the Render Output / Save image settings, the sRGB gamma curve is embedded and the image appears as in the frame buffer when loaded in an external image viewer.
If a 32bit (exr, hdr, tif) image is saved, it remains linear and relies on the external image viewer to handle the gamma.
Reinhard with Burn Value
In case a Reinhard type was used in V-Ray 2.0 and the Burn Value was changed, the same effect can now be achieved with the Highlight Burn control in the Color Corrections/Exposure rollout of the VFB.
V-Ray 2.0 was relying on the Linear workflow option (if enabled) to manage gamma of scene colors and textures. In V-Ray 3.4 this option is hidden and disabled. For backwards compatibility, a Linear workflow checkbox was added to the Layer Options of the V-Ray BRDF, Diffuse BRDF, Reflection and Refraction BRDF material layers. If a V-Ray 2 material is loaded in V-Ray 3, the checkbox is enabled to assure that the material renders the same way as before.
If a new material is created in V-Ray 3.4, the option is disabled.
Because of the above, copying textures or colors from V-Ray 2.0 to V-Ray 3.4 material (or the opposite) might lead to differences in the rendered result.